<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>滚动页面</title>
  <link rel="stylesheet" href="styles.css">
  <style>
    body,
    html {
      margin: 0;
      padding: 0;
      overflow: hidden;
    }

    #scrollContainer {
      width: 100%;
      height: 100vh;
      overflow: hidden;
      position: relative;
    }

    #scrollContent {
      display: flex;
      flex-direction: column;
      transition: transform 0.3s ease;
    }

    .item {
      width: 100%;
      height: 100vh;
      display: flex;
      justify-content: center;
      align-items: center;
      font-size: 5em;
      color: white;
    }

    .item:nth-child(odd) {
      background-color: #333;
    }

    .item:nth-child(even) {
      background-color: #666;
    }
  </style>
</head>

<body>
  <div id="scrollContainer">
    <div id="scrollContent">
      <div class="item">1</div>
      <div class="item">2</div>
      <div class="item">3</div>
      <div class="item">4</div>
      <div class="item">5</div>
    </div>
  </div>
</body>

<script>
  const scrollContainer = document.getElementById('scrollContainer');
  const scrollContent = document.getElementById('scrollContent');
  
  let currentPosition = 0;
  let intervalId = null;
  const scrollDistance = 2;
  const itemHeight = scrollContent.clientHeight / scrollContent.children.length;
  const maxScrollPosition = 0;
  const minScrollPosition = -itemHeight * (scrollContent.children.length - 1);

  function autoScroll() {
    if (currentPosition <= minScrollPosition) {
      currentPosition = 0;
    }
    scrollContent.style.transform = `translateY(${currentPosition}px)`;
    currentPosition -= scrollDistance;
  }

  function startAutoScroll() {
    intervalId = setInterval(autoScroll, 20);
  }

  function stopAutoScroll() {
    clearInterval(intervalId);
  }

  function handleWheel(event) {
    currentPosition -= event.deltaY;
    if (currentPosition > maxScrollPosition) {
      currentPosition = maxScrollPosition;
    } else if (currentPosition < minScrollPosition) {
      currentPosition = minScrollPosition;
    }
    scrollContent.style.transform = `translateY(${currentPosition}px)`;
  }

  scrollContainer.addEventListener('mouseenter', function () {
    stopAutoScroll();
    scrollContainer.addEventListener('wheel', handleWheel);
  });

  scrollContainer.addEventListener('mouseleave', function () {
    scrollContainer.removeEventListener('wheel', handleWheel);
    startAutoScroll();
  });

  startAutoScroll();
</script>

</html>
